[PATCH v3 0/3] Add tests trying to memblock_add() or memblock_reserve() 129th region

[PATCH v3 0/3] Add tests trying to memblock_add() or memblock_reserve() 129th region

[shaoqin.huang]

From: Shaoqin Huang <shaoqin.huang@intel.com>

These tests is aimed for testing the memblock_double_array() can work normal. It
will using the dummy_physical_memory_init() to add the valid memory region into
the memblock.memory, and this memory region will be choosed when
memblock_double_array() to allocate the new memory region to double the regions.
Thus the new memory.regions or reserved.regions will occupy the valid memory
region, and the memory.max and reserved.max also being doubled. Check all of
these changed stuff, to make sure it actually success.

Changelog:
----------
v3:
  - Avoid to allocated multiple memory region from dummy_physical_memory_base(),
  split the memory into different part instead.
  - Some comments improvement.
v2:
  - Modify the get_memory_block_base() to dummy_physical_memory_base().
  - memory_add() the memory which is allocated from dummy_physical_memory_init()
  instead of some faked memory.
  - Add more comments to illustrate the test process.
  - Add a function dummy_physical_memory_cleanup_many() to free multiple memory
  which is allocated from dummy_physical_memory_init().

Shaoqin Huang (3):
  memblock test: Add test to memblock_add() 129th region
  memblock test: Add test to memblock_reserve() 129th region
  memblock test: Update TODO list

 tools/testing/memblock/TODO              |  11 +-
 tools/testing/memblock/tests/basic_api.c | 186 +++++++++++++++++++++++
 tools/testing/memblock/tests/common.c    |   7 +-
 tools/testing/memblock/tests/common.h    |   3 +
 4 files changed, 196 insertions(+), 11 deletions(-)

-- 
2.34.1

[PATCH v3 1/3] memblock test: Add test to memblock_add() 129th region

[shaoqin.huang]

From: Shaoqin Huang <shaoqin.huang@intel.com>

Add 129th region into the memblock, and this will trigger the
memblock_double_array() function, this needs valid memory regions. So
using dummy_physical_memory_init() to allocate a large enough memory
region, and split it into a large enough memory which can be choosed by
memblock_double_array(), and the left memory will be split into small
memory region, and add them into the memblock. It make sure the
memblock_double_array() will always choose the valid memory region that
is allocated by the dummy_physical_memory_init().
So memblock_double_array() must success.

Another thing should be done is to restore the memory.regions after
memblock_double_array(), due to now the memory.regions is pointing to a
memory region allocated by dummy_physical_memory_init(). And it will
affect the subsequent tests if we don't restore the memory region. So
simply record the origin region, and restore it after the test.

Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com>
---
 tools/testing/memblock/tests/basic_api.c | 96 ++++++++++++++++++++++++
 tools/testing/memblock/tests/common.c    |  7 +-
 tools/testing/memblock/tests/common.h    |  3 +
 3 files changed, 104 insertions(+), 2 deletions(-)

diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
index a13a57ba0815..7120fd8e47b1 100644
--- a/tools/testing/memblock/tests/basic_api.c
+++ b/tools/testing/memblock/tests/basic_api.c
@@ -423,6 +423,101 @@ static int memblock_add_near_max_check(void)
 	return 0;
 }
 
+/*
+ * A test that trying to add the 129th memory block.
+ * Expect to trigger memblock_double_array() to double the
+ * memblock.memory.max, find a new valid memory as
+ * memory.regions.
+ */
+static int memblock_add_many_check(void)
+{
+	int i;
+	void *orig_region;
+	struct region r = {
+		.base = SZ_16K,
+		.size = MEM_SIZE,
+	};
+	phys_addr_t new_memory_regions_size;
+	phys_addr_t base, size, block_size;
+
+	PREFIX_PUSH();
+
+	reset_memblock_regions();
+	memblock_allow_resize();
+
+	dummy_physical_memory_init();
+	/*
+	 * We allocated enough memory by using dummy_physical_memory_init(), and
+	 * split it into small block. First we split a large enough memory block
+	 * as the memory region which will be choosed by memblock_double_array().
+	 */
+	base = PAGE_ALIGN(dummy_physical_memory_base());
+	new_memory_regions_size = PAGE_ALIGN(INIT_MEMBLOCK_REGIONS * 2 *
+					     sizeof(struct memblock_region));
+	memblock_add(base, new_memory_regions_size);
+
+	/*
+	 * For the left memory, we split them into small block and add them into
+	 * memblock later.
+	 */
+	base += new_memory_regions_size;
+	size = MEM_SIZE - new_memory_regions_size;
+	block_size = size / (INIT_MEMBLOCK_REGIONS * 2);
+
+	orig_region = memblock.memory.regions;
+
+	for (i = 0; i < INIT_MEMBLOCK_REGIONS; i++) {
+		/*
+		 * Add these small block to fulfill the memblock. We keep an
+		 * interval between the nearby memory to avoid being merged.
+		 */
+		memblock_add(base + block_size * (2 * i + 1), block_size);
+
+		ASSERT_EQ(memblock.memory.cnt, i + 2);
+		ASSERT_EQ(memblock.memory.total_size, new_memory_regions_size +
+						      (i + 1) * block_size);
+	}
+
+	/*
+	 * At there, memblock_double_array() has been succeed, check if it
+	 * update the memory.max.
+	 */
+	ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
+
+	/* memblock_double_array() will reserve the memory it used. Check it. */
+	ASSERT_EQ(memblock.reserved.cnt, 1);
+	ASSERT_EQ(memblock.reserved.total_size, new_memory_regions_size);
+
+	/*
+	 * Now memblock_double_array() works fine. Let's check after the
+	 * double_array(), the memblock_add() still works as normal.
+	 */
+	memblock_add(r.base, r.size);
+	ASSERT_EQ(memblock.memory.regions[0].base, r.base);
+	ASSERT_EQ(memblock.memory.regions[0].size, r.size);
+
+	ASSERT_EQ(memblock.memory.cnt, INIT_MEMBLOCK_REGIONS + 2);
+	ASSERT_EQ(memblock.memory.total_size, INIT_MEMBLOCK_REGIONS * block_size +
+					      new_memory_regions_size +
+					      MEM_SIZE);
+	ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
+
+	dummy_physical_memory_cleanup();
+
+	/*
+	 * The current memory.regions is occupying a range of memory that
+	 * allocated from dummy_physical_memory_init(). After free the memory,
+	 * we must not use it. So restore the origin memory region to make sure
+	 * the tests can run as normal and not affected by the double array.
+	 */
+	memblock.memory.regions = orig_region;
+	memblock.memory.cnt = INIT_MEMBLOCK_REGIONS;
+
+	test_pass_pop();
+
+	return 0;
+}
+
 static int memblock_add_checks(void)
 {
 	prefix_reset();
@@ -438,6 +533,7 @@ static int memblock_add_checks(void)
 	memblock_add_twice_check();
 	memblock_add_between_check();
 	memblock_add_near_max_check();
+	memblock_add_many_check();
 
 	prefix_pop();
 
diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c
index eec6901081af..2de6a2b6efd2 100644
--- a/tools/testing/memblock/tests/common.c
+++ b/tools/testing/memblock/tests/common.c
@@ -5,8 +5,6 @@
 #include <linux/memory_hotplug.h>
 #include <linux/build_bug.h>
 
-#define INIT_MEMBLOCK_REGIONS			128
-#define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
 #define PREFIXES_MAX				15
 #define DELIM					": "
 
@@ -84,6 +82,11 @@ void dummy_physical_memory_cleanup(void)
 	free(memory_block.base);
 }
 
+phys_addr_t dummy_physical_memory_base(void)
+{
+	return (phys_addr_t)memory_block.base;
+}
+
 static void usage(const char *prog)
 {
 	BUILD_BUG_ON(ARRAY_SIZE(help_opts) != ARRAY_SIZE(long_opts) - 1);
diff --git a/tools/testing/memblock/tests/common.h b/tools/testing/memblock/tests/common.h
index 78128e109a95..ba14dc989ae9 100644
--- a/tools/testing/memblock/tests/common.h
+++ b/tools/testing/memblock/tests/common.h
@@ -11,6 +11,8 @@
 #include <../selftests/kselftest.h>
 
 #define MEM_SIZE SZ_16K
+#define INIT_MEMBLOCK_REGIONS			128
+#define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
 
 enum test_flags {
 	/* No special request. */
@@ -104,6 +106,7 @@ void reset_memblock_attributes(void);
 void setup_memblock(void);
 void dummy_physical_memory_init(void);
 void dummy_physical_memory_cleanup(void);
+phys_addr_t dummy_physical_memory_base(void);
 void parse_args(int argc, char **argv);
 
 void test_fail(void);
-- 
2.34.1

[PATCH v3 2/3] memblock test: Add test to memblock_reserve() 129th region

[shaoqin.huang]

From: Shaoqin Huang <shaoqin.huang@intel.com>

Reserve 129th region in the memblock, and this will trigger the
memblock_double_array() function, this needs valid memory regions. So
using dummy_physical_memory_init() to allocate a valid memory region.
At the same time, reserve 128 faked memory region, and make sure these
reserved region not intersect with the valid memory region. So
memblock_double_array() will choose the valid memory region, and it will
success.

Also need to restore the reserved.regions after memblock_double_array(),
to make sure the subsequent tests can run as normal.

Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com>
---
 tools/testing/memblock/tests/basic_api.c | 90 ++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
index 7120fd8e47b1..1924524ad868 100644
--- a/tools/testing/memblock/tests/basic_api.c
+++ b/tools/testing/memblock/tests/basic_api.c
@@ -895,6 +895,95 @@ static int memblock_reserve_near_max_check(void)
 	return 0;
 }
 
+/*
+ * A test that trying to reserve the 129th memory block.
+ * Expect to trigger memblock_double_array() to double the
+ * memblock.memory.max, find a new valid memory as
+ * reserved.regions.
+ */
+static int memblock_reserve_many_check(void)
+{
+	int i;
+	void *orig_region;
+	struct region r = {
+		.base = SZ_16K,
+		.size = MEM_SIZE,
+	};
+	phys_addr_t memory_base = SZ_128K;
+	phys_addr_t new_reserved_regions_size;
+
+	PREFIX_PUSH();
+
+	reset_memblock_regions();
+	memblock_allow_resize();
+
+	/* Add a valid memory region used by double_array(). */
+	dummy_physical_memory_init();
+	memblock_add(dummy_physical_memory_base(), MEM_SIZE);
+
+	for (i = 0; i < INIT_MEMBLOCK_REGIONS; i++) {
+		/* Reserve some fakes memory region to fulfill the memblock. */
+		memblock_reserve(memory_base, MEM_SIZE);
+
+		ASSERT_EQ(memblock.reserved.cnt, i + 1);
+		ASSERT_EQ(memblock.reserved.total_size, (i + 1) * MEM_SIZE);
+
+		/* Keep the gap so these memory region will not be merged. */
+		memory_base += MEM_SIZE * 2;
+	}
+
+	orig_region = memblock.reserved.regions;
+
+	/* This reserve the 129 memory_region, and makes it double array. */
+	memblock_reserve(memory_base, MEM_SIZE);
+
+	/*
+	 * This is the memory region size used by the doubled reserved.regions,
+	 * and it has been reserved due to it has been used. The size is used to
+	 * calculate the total_size that the memblock.reserved have now.
+	 */
+	new_reserved_regions_size = PAGE_ALIGN((INIT_MEMBLOCK_REGIONS * 2) *
+					sizeof(struct memblock_region));
+	/*
+	 * The double_array() will find a free memory region as the new
+	 * reserved.regions, and the used memory region will be reserved, so
+	 * there will be one more region exist in the reserved memblock. And the
+	 * one more reserved region's size is new_reserved_regions_size.
+	 */
+	ASSERT_EQ(memblock.reserved.cnt, INIT_MEMBLOCK_REGIONS + 2);
+	ASSERT_EQ(memblock.reserved.total_size, (INIT_MEMBLOCK_REGIONS + 1) * MEM_SIZE +
+						new_reserved_regions_size);
+	ASSERT_EQ(memblock.reserved.max, INIT_MEMBLOCK_REGIONS * 2);
+
+	/*
+	 * Now memblock_double_array() works fine. Let's check after the
+	 * double_array(), the memblock_reserve() still works as normal.
+	 */
+	memblock_reserve(r.base, r.size);
+	ASSERT_EQ(memblock.reserved.regions[0].base, r.base);
+	ASSERT_EQ(memblock.reserved.regions[0].size, r.size);
+
+	ASSERT_EQ(memblock.reserved.cnt, INIT_MEMBLOCK_REGIONS + 3);
+	ASSERT_EQ(memblock.reserved.total_size, (INIT_MEMBLOCK_REGIONS + 2) * MEM_SIZE +
+						new_reserved_regions_size);
+	ASSERT_EQ(memblock.reserved.max, INIT_MEMBLOCK_REGIONS * 2);
+
+	dummy_physical_memory_cleanup();
+
+	/*
+	 * The current reserved.regions is occupying a range of memory that
+	 * allocated from dummy_physical_memory_init(). After free the memory,
+	 * we must not use it. So restore the origin memory region to make sure
+	 * the tests can run as normal and not affected by the double array.
+	 */
+	memblock.reserved.regions = orig_region;
+	memblock.reserved.cnt = INIT_MEMBLOCK_REGIONS;
+
+	test_pass_pop();
+
+	return 0;
+}
+
 static int memblock_reserve_checks(void)
 {
 	prefix_reset();
@@ -909,6 +998,7 @@ static int memblock_reserve_checks(void)
 	memblock_reserve_twice_check();
 	memblock_reserve_between_check();
 	memblock_reserve_near_max_check();
+	memblock_reserve_many_check();
 
 	prefix_pop();
 
-- 
2.34.1

[PATCH v3 3/3] memblock test: Update TODO list

[shaoqin.huang]

From: Shaoqin Huang <shaoqin.huang@intel.com>

Remove the completed items from TODO list.

Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com>
---
 tools/testing/memblock/TODO | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/tools/testing/memblock/TODO b/tools/testing/memblock/TODO
index 33044c634ea7..503cc96fcdc3 100644
--- a/tools/testing/memblock/TODO
+++ b/tools/testing/memblock/TODO
@@ -1,17 +1,10 @@
 TODO
 =====
 
-1. Add tests trying to memblock_add() or memblock_reserve() 129th region.
-   This will trigger memblock_double_array(), make sure it succeeds.
-   *Important:* These tests require valid memory ranges, use dummy physical
-                memory block from common.c to implement them. It is also very
-                likely that the current MEM_SIZE won't be enough for these
-                test cases. Use realloc to adjust the size accordingly.
-
-2. Add test cases using this functions (implement them for both directions):
+1. Add test cases using this functions (implement them for both directions):
    + memblock_alloc_raw()
    + memblock_alloc_exact_nid_raw()
    + memblock_alloc_try_nid_raw()
 
-3. Add tests for memblock_alloc_node() to check if the correct NUMA node is set
+2. Add tests for memblock_alloc_node() to check if the correct NUMA node is set
    for the new region
-- 
2.34.1

Re: [PATCH v3 1/3] memblock test: Add test to memblock_add() 129th region

[Mike Rapoport]

On Tue, Sep 13, 2022 at 02:41:30PM +0800, shaoqin.huang@intel.com wrote:
> From: Shaoqin Huang <shaoqin.huang@intel.com>
> 
> Add 129th region into the memblock, and this will trigger the
> memblock_double_array() function, this needs valid memory regions. So
> using dummy_physical_memory_init() to allocate a large enough memory
> region, and split it into a large enough memory which can be choosed by
> memblock_double_array(), and the left memory will be split into small
> memory region, and add them into the memblock. It make sure the
> memblock_double_array() will always choose the valid memory region that
> is allocated by the dummy_physical_memory_init().
> So memblock_double_array() must success.
> 
> Another thing should be done is to restore the memory.regions after
> memblock_double_array(), due to now the memory.regions is pointing to a
> memory region allocated by dummy_physical_memory_init(). And it will
> affect the subsequent tests if we don't restore the memory region. So
> simply record the origin region, and restore it after the test.
> 
> Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com>
> ---
>  tools/testing/memblock/tests/basic_api.c | 96 ++++++++++++++++++++++++
>  tools/testing/memblock/tests/common.c    |  7 +-
>  tools/testing/memblock/tests/common.h    |  3 +
>  3 files changed, 104 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
> index a13a57ba0815..7120fd8e47b1 100644
> --- a/tools/testing/memblock/tests/basic_api.c
> +++ b/tools/testing/memblock/tests/basic_api.c
> @@ -423,6 +423,101 @@ static int memblock_add_near_max_check(void)
>  	return 0;
>  }
>  
> +/*
> + * A test that trying to add the 129th memory block.
> + * Expect to trigger memblock_double_array() to double the
> + * memblock.memory.max, find a new valid memory as
> + * memory.regions.
> + */
> +static int memblock_add_many_check(void)
> +{
> +	int i;
> +	void *orig_region;
> +	struct region r = {
> +		.base = SZ_16K,
> +		.size = MEM_SIZE,
> +	};
> +	phys_addr_t new_memory_regions_size;
> +	phys_addr_t base, size, block_size;
> +
> +	PREFIX_PUSH();
> +
> +	reset_memblock_regions();
> +	memblock_allow_resize();
> +
> +	dummy_physical_memory_init();
> +	/*
> +	 * We allocated enough memory by using dummy_physical_memory_init(), and
> +	 * split it into small block. First we split a large enough memory block
> +	 * as the memory region which will be choosed by memblock_double_array().
> +	 */
> +	base = PAGE_ALIGN(dummy_physical_memory_base());
> +	new_memory_regions_size = PAGE_ALIGN(INIT_MEMBLOCK_REGIONS * 2 *
> +					     sizeof(struct memblock_region));
> +	memblock_add(base, new_memory_regions_size);

Why don't you simply increase MEM_SIZE, to say 1M?
This will make all the calculations here way simpler.

> +
> +	/*
> +	 * For the left memory, we split them into small block and add them into
> +	 * memblock later.
> +	 */
> +	base += new_memory_regions_size;
> +	size = MEM_SIZE - new_memory_regions_size;
> +	block_size = size / (INIT_MEMBLOCK_REGIONS * 2);
> +
> +	orig_region = memblock.memory.regions;
> +
> +	for (i = 0; i < INIT_MEMBLOCK_REGIONS; i++) {
> +		/*
> +		 * Add these small block to fulfill the memblock. We keep an
> +		 * interval between the nearby memory to avoid being merged.
> +		 */
> +		memblock_add(base + block_size * (2 * i + 1), block_size);
> +
> +		ASSERT_EQ(memblock.memory.cnt, i + 2);
> +		ASSERT_EQ(memblock.memory.total_size, new_memory_regions_size +
> +						      (i + 1) * block_size);
> +	}
> +
> +	/*
> +	 * At there, memblock_double_array() has been succeed, check if it
> +	 * update the memory.max.
> +	 */
> +	ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
> +
> +	/* memblock_double_array() will reserve the memory it used. Check it. */
> +	ASSERT_EQ(memblock.reserved.cnt, 1);
> +	ASSERT_EQ(memblock.reserved.total_size, new_memory_regions_size);
> +
> +	/*
> +	 * Now memblock_double_array() works fine. Let's check after the
> +	 * double_array(), the memblock_add() still works as normal.
> +	 */
> +	memblock_add(r.base, r.size);
> +	ASSERT_EQ(memblock.memory.regions[0].base, r.base);
> +	ASSERT_EQ(memblock.memory.regions[0].size, r.size);
> +
> +	ASSERT_EQ(memblock.memory.cnt, INIT_MEMBLOCK_REGIONS + 2);
> +	ASSERT_EQ(memblock.memory.total_size, INIT_MEMBLOCK_REGIONS * block_size +
> +					      new_memory_regions_size +
> +					      MEM_SIZE);
> +	ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
> +
> +	dummy_physical_memory_cleanup();
> +
> +	/*
> +	 * The current memory.regions is occupying a range of memory that
> +	 * allocated from dummy_physical_memory_init(). After free the memory,
> +	 * we must not use it. So restore the origin memory region to make sure
> +	 * the tests can run as normal and not affected by the double array.
> +	 */
> +	memblock.memory.regions = orig_region;
> +	memblock.memory.cnt = INIT_MEMBLOCK_REGIONS;
> +
> +	test_pass_pop();
> +
> +	return 0;
> +}
> +
>  static int memblock_add_checks(void)
>  {
>  	prefix_reset();
> @@ -438,6 +533,7 @@ static int memblock_add_checks(void)
>  	memblock_add_twice_check();
>  	memblock_add_between_check();
>  	memblock_add_near_max_check();
> +	memblock_add_many_check();
>  
>  	prefix_pop();
>  
> diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c
> index eec6901081af..2de6a2b6efd2 100644
> --- a/tools/testing/memblock/tests/common.c
> +++ b/tools/testing/memblock/tests/common.c
> @@ -5,8 +5,6 @@
>  #include <linux/memory_hotplug.h>
>  #include <linux/build_bug.h>
>  
> -#define INIT_MEMBLOCK_REGIONS			128
> -#define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
>  #define PREFIXES_MAX				15
>  #define DELIM					": "
>  
> @@ -84,6 +82,11 @@ void dummy_physical_memory_cleanup(void)
>  	free(memory_block.base);
>  }
>  
> +phys_addr_t dummy_physical_memory_base(void)
> +{
> +	return (phys_addr_t)memory_block.base;
> +}
> +
>  static void usage(const char *prog)
>  {
>  	BUILD_BUG_ON(ARRAY_SIZE(help_opts) != ARRAY_SIZE(long_opts) - 1);
> diff --git a/tools/testing/memblock/tests/common.h b/tools/testing/memblock/tests/common.h
> index 78128e109a95..ba14dc989ae9 100644
> --- a/tools/testing/memblock/tests/common.h
> +++ b/tools/testing/memblock/tests/common.h
> @@ -11,6 +11,8 @@
>  #include <../selftests/kselftest.h>
>  
>  #define MEM_SIZE SZ_16K
> +#define INIT_MEMBLOCK_REGIONS			128
> +#define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
>  
>  enum test_flags {
>  	/* No special request. */
> @@ -104,6 +106,7 @@ void reset_memblock_attributes(void);
>  void setup_memblock(void);
>  void dummy_physical_memory_init(void);
>  void dummy_physical_memory_cleanup(void);
> +phys_addr_t dummy_physical_memory_base(void);
>  void parse_args(int argc, char **argv);
>  
>  void test_fail(void);
> -- 
> 2.34.1
> 
> 

-- 
Sincerely yours,
Mike.

Re: [PATCH v3 1/3] memblock test: Add test to memblock_add() 129th region

[Huang, Shaoqin]

On 9/18/2022 5:25 PM, Mike Rapoport wrote:
> On Tue, Sep 13, 2022 at 02:41:30PM +0800, shaoqin.huang@intel.com wrote:
>> From: Shaoqin Huang <shaoqin.huang@intel.com>
>>
>> Add 129th region into the memblock, and this will trigger the
>> memblock_double_array() function, this needs valid memory regions. So
>> using dummy_physical_memory_init() to allocate a large enough memory
>> region, and split it into a large enough memory which can be choosed by
>> memblock_double_array(), and the left memory will be split into small
>> memory region, and add them into the memblock. It make sure the
>> memblock_double_array() will always choose the valid memory region that
>> is allocated by the dummy_physical_memory_init().
>> So memblock_double_array() must success.
>>
>> Another thing should be done is to restore the memory.regions after
>> memblock_double_array(), due to now the memory.regions is pointing to a
>> memory region allocated by dummy_physical_memory_init(). And it will
>> affect the subsequent tests if we don't restore the memory region. So
>> simply record the origin region, and restore it after the test.
>>
>> Signed-off-by: Shaoqin Huang <shaoqin.huang@intel.com>
>> ---
>>   tools/testing/memblock/tests/basic_api.c | 96 ++++++++++++++++++++++++
>>   tools/testing/memblock/tests/common.c    |  7 +-
>>   tools/testing/memblock/tests/common.h    |  3 +
>>   3 files changed, 104 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
>> index a13a57ba0815..7120fd8e47b1 100644
>> --- a/tools/testing/memblock/tests/basic_api.c
>> +++ b/tools/testing/memblock/tests/basic_api.c
>> @@ -423,6 +423,101 @@ static int memblock_add_near_max_check(void)
>>   	return 0;
>>   }
>>   
>> +/*
>> + * A test that trying to add the 129th memory block.
>> + * Expect to trigger memblock_double_array() to double the
>> + * memblock.memory.max, find a new valid memory as
>> + * memory.regions.
>> + */
>> +static int memblock_add_many_check(void)
>> +{
>> +	int i;
>> +	void *orig_region;
>> +	struct region r = {
>> +		.base = SZ_16K,
>> +		.size = MEM_SIZE,
>> +	};
>> +	phys_addr_t new_memory_regions_size;
>> +	phys_addr_t base, size, block_size;
>> +
>> +	PREFIX_PUSH();
>> +
>> +	reset_memblock_regions();
>> +	memblock_allow_resize();
>> +
>> +	dummy_physical_memory_init();
>> +	/*
>> +	 * We allocated enough memory by using dummy_physical_memory_init(), and
>> +	 * split it into small block. First we split a large enough memory block
>> +	 * as the memory region which will be choosed by memblock_double_array().
>> +	 */
>> +	base = PAGE_ALIGN(dummy_physical_memory_base());
>> +	new_memory_regions_size = PAGE_ALIGN(INIT_MEMBLOCK_REGIONS * 2 *
>> +					     sizeof(struct memblock_region));
>> +	memblock_add(base, new_memory_regions_size);
> 
> Why don't you simply increase MEM_SIZE, to say 1M?
> This will make all the calculations here way simpler.
> 

Ok. I will increase MEM_SIZE. That can clean the calculation.

>> +
>> +	/*
>> +	 * For the left memory, we split them into small block and add them into
>> +	 * memblock later.
>> +	 */
>> +	base += new_memory_regions_size;
>> +	size = MEM_SIZE - new_memory_regions_size;
>> +	block_size = size / (INIT_MEMBLOCK_REGIONS * 2);
>> +
>> +	orig_region = memblock.memory.regions;
>> +
>> +	for (i = 0; i < INIT_MEMBLOCK_REGIONS; i++) {
>> +		/*
>> +		 * Add these small block to fulfill the memblock. We keep an
>> +		 * interval between the nearby memory to avoid being merged.
>> +		 */
>> +		memblock_add(base + block_size * (2 * i + 1), block_size);
>> +
>> +		ASSERT_EQ(memblock.memory.cnt, i + 2);
>> +		ASSERT_EQ(memblock.memory.total_size, new_memory_regions_size +
>> +						      (i + 1) * block_size);
>> +	}
>> +
>> +	/*
>> +	 * At there, memblock_double_array() has been succeed, check if it
>> +	 * update the memory.max.
>> +	 */
>> +	ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
>> +
>> +	/* memblock_double_array() will reserve the memory it used. Check it. */
>> +	ASSERT_EQ(memblock.reserved.cnt, 1);
>> +	ASSERT_EQ(memblock.reserved.total_size, new_memory_regions_size);
>> +
>> +	/*
>> +	 * Now memblock_double_array() works fine. Let's check after the
>> +	 * double_array(), the memblock_add() still works as normal.
>> +	 */
>> +	memblock_add(r.base, r.size);
>> +	ASSERT_EQ(memblock.memory.regions[0].base, r.base);
>> +	ASSERT_EQ(memblock.memory.regions[0].size, r.size);
>> +
>> +	ASSERT_EQ(memblock.memory.cnt, INIT_MEMBLOCK_REGIONS + 2);
>> +	ASSERT_EQ(memblock.memory.total_size, INIT_MEMBLOCK_REGIONS * block_size +
>> +					      new_memory_regions_size +
>> +					      MEM_SIZE);
>> +	ASSERT_EQ(memblock.memory.max, INIT_MEMBLOCK_REGIONS * 2);
>> +
>> +	dummy_physical_memory_cleanup();
>> +
>> +	/*
>> +	 * The current memory.regions is occupying a range of memory that
>> +	 * allocated from dummy_physical_memory_init(). After free the memory,
>> +	 * we must not use it. So restore the origin memory region to make sure
>> +	 * the tests can run as normal and not affected by the double array.
>> +	 */
>> +	memblock.memory.regions = orig_region;
>> +	memblock.memory.cnt = INIT_MEMBLOCK_REGIONS;
>> +
>> +	test_pass_pop();
>> +
>> +	return 0;
>> +}
>> +
>>   static int memblock_add_checks(void)
>>   {
>>   	prefix_reset();
>> @@ -438,6 +533,7 @@ static int memblock_add_checks(void)
>>   	memblock_add_twice_check();
>>   	memblock_add_between_check();
>>   	memblock_add_near_max_check();
>> +	memblock_add_many_check();
>>   
>>   	prefix_pop();
>>   
>> diff --git a/tools/testing/memblock/tests/common.c b/tools/testing/memblock/tests/common.c
>> index eec6901081af..2de6a2b6efd2 100644
>> --- a/tools/testing/memblock/tests/common.c
>> +++ b/tools/testing/memblock/tests/common.c
>> @@ -5,8 +5,6 @@
>>   #include <linux/memory_hotplug.h>
>>   #include <linux/build_bug.h>
>>   
>> -#define INIT_MEMBLOCK_REGIONS			128
>> -#define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
>>   #define PREFIXES_MAX				15
>>   #define DELIM					": "
>>   
>> @@ -84,6 +82,11 @@ void dummy_physical_memory_cleanup(void)
>>   	free(memory_block.base);
>>   }
>>   
>> +phys_addr_t dummy_physical_memory_base(void)
>> +{
>> +	return (phys_addr_t)memory_block.base;
>> +}
>> +
>>   static void usage(const char *prog)
>>   {
>>   	BUILD_BUG_ON(ARRAY_SIZE(help_opts) != ARRAY_SIZE(long_opts) - 1);
>> diff --git a/tools/testing/memblock/tests/common.h b/tools/testing/memblock/tests/common.h
>> index 78128e109a95..ba14dc989ae9 100644
>> --- a/tools/testing/memblock/tests/common.h
>> +++ b/tools/testing/memblock/tests/common.h
>> @@ -11,6 +11,8 @@
>>   #include <../selftests/kselftest.h>
>>   
>>   #define MEM_SIZE SZ_16K
>> +#define INIT_MEMBLOCK_REGIONS			128
>> +#define INIT_MEMBLOCK_RESERVED_REGIONS		INIT_MEMBLOCK_REGIONS
>>   
>>   enum test_flags {
>>   	/* No special request. */
>> @@ -104,6 +106,7 @@ void reset_memblock_attributes(void);
>>   void setup_memblock(void);
>>   void dummy_physical_memory_init(void);
>>   void dummy_physical_memory_cleanup(void);
>> +phys_addr_t dummy_physical_memory_base(void);
>>   void parse_args(int argc, char **argv);
>>   
>>   void test_fail(void);
>> -- 
>> 2.34.1
>>
>>
>